GROSS domestic product (GDP) accelerated to 2.1% on a seasonally adjusted and annualised basis in the fourth quarter of last year from 1.2% in the third quarter, Statistics South Africa figures released on Tuesday showed.
Consensus forecasts had forecast a slight pickup to 1.8%, seasonally adjusted and annualised.
GDP increased as expected by 2.5% last year following an increase of 3.5% in 2011.
The main contributors to the 2.1% increase in economic activity in the fourth quarter of last year were the manufacturing industry (0.8 percentage points); finance, real estate and business services (0.6 percentage points); and general government services (0.4 percentage points).
The mining and quarrying industry recorded a negative contribution of 0.5 percentage points, and the contributions by the electricity, gas and water industry and the construction industry were insignificant.
Statistics South Africa officials said the negative contribution from the mining sector was not solely attributed to strikes that occurred in the second half of last year, but was due to a "combination of factors".
"There are still cost effects as well.... Mining companies have complained about costs," Stats SA GDP manager Kedibone Mabaso said.
The rand firmed against the dollar on Tuesday after the data, strengthening to R8.7835 to the dollar, from R8.8475 before the data were released.
Investec chief economist Annabel Bishop said the quarterly growth number was "essentially in line with our own forecast of 2.2%".
"While economic growth is still below the potential, the fourth quarter of 2012 was impacted by the lagged effect of the strike action and growth is expected to strengthen in the first quarter of 2013," Ms Bishop said.
"The new CPI (consumer price index) inflation series has now been published and higher inflation is likely in the months ahead due to sharply higher fuel prices and recent rand weakness. We continue to expect that interest rates will remain unchanged this year."
Kadd Capital economist Elize Kruger said: "The data was closer to my forecast of 2% but better than market consensus. It shows there was life in the manufacturing sector, which helped offset the drop in the mining output in the quarter on review due to labour unrest."
Ms Kruger said her company was not very positive about 2013 and expected growth for the year to come in at 2.7%.
"Obviously we need a lot more growth to help us grow ourselves away from our problems," she said.
Renaissance Capital economist Elna Moolman noted strong performances from the agricultural sector "and a shallower-than-expected contraction in mining GDP (down 9%)" as reasons for the stronger than expected growth.
Nonetheless, she said, "we still expect only a modest acceleration in growth in 2013 (to around 2.7%) from 2.5% in 2012".
"In terms of our view that consumer spending will continue to slow, the moderation in (growth in) the wholesale and retail sector — 1.5% quarter on quarter, from 1.7% in the third quarter and 5% a year earlier — is important."